Convert Femtocoulombs per kilogram to Roentgens
Convert Femtocoulombs per kilogram (fC/kg) to Roentgens (R) instantly and accurately.
Conversion Formula
R = fC/kg × 3.875968992e-12
About Femtocoulombs per kilogram
The femtocoulomb per kilogram (fC/kg) equals 10⁻¹⁵ C/kg. Used in computational dosimetry to characterise the ionisation yield from single low-energy photon interactions in nanogram air volumes; ultra-sensitive free-air ionisation chamber simulations in microdosimetry research report air-ionisation at the fC/kg level. 1 fC/kg = 10⁻¹⁵ C/kg = 10⁻³ pC/kg.
About Roentgens
The roentgen (R) equals exactly 2.58 × 10⁻⁴ C/kg, the historical unit of X-ray and gamma-ray exposure defined in 1928 (ICRU) and redefined exactly in 1962. Still widely used in the US: field survey instruments read in R/h; NRC and EPA regulations cite R and mR; the Chernobyl accounts famously reported readings in R/h. 1 R = 2.58 × 10⁻⁴ C/kg.
Quick Reference Table
| Femtocoulombs per kilogram (fC/kg) | Roentgens (R) |
|---|---|
| 1 fC/kg | 3.876 × 10-12 R |
| 2 fC/kg | 7.752 × 10-12 R |
| 5 fC/kg | 1.938 × 10-11 R |
| 10 fC/kg | 3.876 × 10-11 R |
| 25 fC/kg | 9.69 × 10-11 R |
| 50 fC/kg | 1.938 × 10-10 R |
| 100 fC/kg | 3.876 × 10-10 R |